Nadis

In addition to the seven chakras of the subtle body, the Tantras have described a network of subtle channels known as nadis through which the life force (prana) circulates.

Nadi means "stream". According to the tantric treatise there are fourteen principal nadis. Of these, Ida, Pingala and Sushumna are considered the most important.

Ida is the left channel. Ida is feminine and represents the moon. Originating in Muladhara, Ida ends up in the left nostril.

Pingala is the right channel. Pingala is masculine and represents the sun. Originating in Muladhara, Pingala ends up in the right nostril.

Sushumna is the central channel. Within the Sushumna nadi there are three more subtle channels: Vajra, Chitra and Brahma nadi through which Kundalini moves upwards from the Muladhara chakra to Sahasrara chakra at the crown of the head.

The Muladhara chakra is the meeting place of the three main nadis. In the Muladhara, Shakti, the static unmanifested Kundalini, is symbolized by a serpent coiled into three and a half circles around the central at the base of the spine.

The technique of awakening Kundalini is in using Prana (the vital air), guiding its circulatory movement through Ida and Pingala down to the base of the spine into the space where Kundalini lies coiled. The vital energies of the opposite forces circulating in Ida and Pingala will be unified and Shakti Kundalini will then awaken and rise up Sushumna, energizing the seven chakras.

From Muladhara chakra, Ida and Pingala alternate from the right to left sides at each chakra until they reach Ajna chakra where they meet again with Sushumna.

Once the Kundalini Shakti has ascended through Sushumna to Sahasrara, the highest psychic center at the crown of the head, it is made to reverse its course and return to rest in the base center again.